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Current Research and Scholarly Interests

For the past 15 years, Dr. Kiernan has conducted research on behavioral weight management at the Stanford Prevention Research Center (SPRC), a Division of the Stanford University Department of Medicine. SPRC is multidisciplinary, focused on research and teaching, and dedicated to the improvement of health through the prevention and effective management of chronic disease influenced by lifestyle behaviors via randomized clinical trials, community intervention studies, and population-based surveys among diverse samples of all ages, ethnic groups, and social strata living in northern Californian communities.

Her research interests include: (1) testing tailored behavioral interventions that promote long-term lifestyle changes and weight management among subgroups at risk; and (2) developing methodological and statistical approaches that improve the design, delivery, and analysis of randomized clinical trials. The latter includes using risk classification methods to better identify subgroups at risk, improving recruitment of ethnic minorities into clinical trials, and clarifying approaches for testing the role of moderators and mediators.

From 2001-2007, Dr. Kiernan was the Research Director of the Scholarly Concentration in Community Health at the Stanford University School of Medicine in which she advised 45+ medical students who conducted individual research projects in collaboration with local and international community health partnerships using mixed methods (qualitative and quantitative) approaches. In 2007, she returned to her primary focus on obesity research, including as PI of the Fresh Start trial (R01 CA112594) designed to test whether learning a set of novel ‘stability skills’ first (i.e., before losing weight) promotes better long-term maintenance of weight loss than traditional maintenance approaches.

Abstract

Background:Physical activity is essential for chronic disease prevention, yet <40% of overweight/obese adults meet the national activity recommendations. For time-efficient counseling, clinicians need a brief, easy-to-use tool that reliably and validly assesses a full range of activity levels, and, most importantly, is sensitive to clinically meaningful changes in activity. The Stanford Leisure-Time Activity Categorical Item (L-Cat) is a single item comprising six descriptive categories ranging from inactive to very active. This novel methodological approach assesses national activity recommendations as well as multiple clinically relevant categories below and above the recommendations, and incorporates critical methodological principles that enhance psychometrics (reliability, validity and sensitivity to change).Methods:We evaluated the L-Cat's psychometrics among 267 overweight/obese women who were asked to meet the national activity recommendations in a randomized behavioral weight-loss trial.Results:The L-Cat had excellent test-retest reliability (?=0.64, P<0.001) and adequate concurrent criterion validity; each L-Cat category at 6 months was associated with 1059 more daily pedometer steps (95% CI 712-1407, ?=0.38, P<0.001) and 1.9% greater initial weight loss at 6 months (95% CI -2.4 to -1.3, ?=-0.38, P<0.001). Of interest, L-Cat categories differentiated from each other in a dose-response gradient for steps and weight loss (Ps<0.05) with excellent face validity. The L-Cat was sensitive to change in response to the trial's activity component. Women increased one L-Cat category at 6 months (M=1.0±1.4, P<0.001); 55.8% met the recommendations at 6 months whereas 20.6% did at baseline (P<0.001). Even among women not meeting the recommendations at both baseline and 6 months (n=106), women who moved ?1?L-Cat categories at 6 months lost more weight than those who did not (M=-4.6%, 95% CI -6.7 to -2.5, P<0.001).Conclusions:Given strong psychometrics, the L-Cat has timely potential for clinical use such as tracking activity changes via electronic medical records, especially among overweight/obese populations who are unable or unlikely to reach national recommendations.International Journal of Obesity advance online publication, 16 April 2013; doi:10.1038/ijo.2013.36.

Abstract

Social support could be a powerful weight-loss treatment moderator or mediator but is rarely assessed. We assessed the psychometric properties, initial levels, and predictive validity of a measure of perceived social support and sabotage from friends and family for healthy eating and physical activity (eight subscales). Overweight/obese women randomized to one of two 6-month, group-based behavioral weight-loss programs (N = 267; mean BMI 32.1 ± 3.5; 66.3% White) completed subscales at baseline, and weight loss was assessed at 6 months. Internal consistency, discriminant validity, and content validity were excellent for support subscales and adequate for sabotage subscales; qualitative responses revealed novel deliberate instances not reflected in current sabotage items. Most women (>75%) "never" or "rarely" experienced support from friends or family. Using nonparametric classification methods, we identified two subscales-support from friends for healthy eating and support from family for physical activity-that predicted three clinically meaningful subgroups who ranged in likelihood of losing ?5% of initial weight at 6 months. Women who "never" experienced family support were least likely to lose weight (45.7% lost weight) whereas women who experienced both frequent friend and family support were more likely to lose weight (71.6% lost weight). Paradoxically, women who "never" experienced friend support were most likely to lose weight (80.0% lost weight), perhaps because the group-based programs provided support lacking from friendships. Psychometrics for support subscales were excellent; initial support was rare; and the differential roles of friend vs. family support could inform future targeted weight-loss interventions to subgroups at risk.

Abstract

Given that retention rates for weight-loss trials have not significantly improved in the past 20 years, identifying effective techniques to enhance retention is critical. This paper describes a conceptual and practical advance that may have improved retention in a behavioral weight-loss trial-the novel application of motivational interviewing techniques to diffuse ambivalence during interactive group-based orientation sessions prior to randomization. These orientation sessions addressed ambivalence about making eating and exercise behavior changes, ambivalence about joining a randomized controlled trial, and unrealistic weight-loss expectations. During these sessions, overweight and obese men and women learned about the health benefits of modest weight loss as well as trial design, the importance of a control condition, random assignment and the impact of dropouts. Participants were then divided into groups of three or four, and asked to generate two pros and two cons of being assigned to a control condition and an active condition. Participants shared their pros and cons with the larger group, while the investigator asked open-ended questions, engaged in reflective listening and avoided taking a 'pro-change' position. Retention was high, with 96% of the participants (N = 162) completing 18-month clinic visits.

Abstract

Racial and ethnic minorities in the US suffer disproportionately from obesity and related comorbidities, yet remain underrepresented in health research. To date, research on practical strategies to improve minority reach and recruitment into clinical trials is primarily descriptive rather than experimental. Within a randomized behavioral weight management trial for obese women, this recruitment experiment examined whether two characteristics of direct mail letters, an ethnically-targeted statement and personalization, increased the response rate among minority women. The ethnically-targeted statement noted ethnic-specific information about health risks of obesity. Personalized letters included recipients' names/addresses in the salutation and a handwritten signature on high-quality letterhead. Of women sent direct mail letters (N=30,000), those sent letters with the ethnically-targeted statement were more likely to respond than women sent letters with the generic statement, 0.8% (n=121) vs. 0.6% (n=90) respectively, p=.03, a 34.4% increase. Women sent personalized letters were no more likely to respond than women sent non-personalized letters, p=.53. In the weight management trial itself, of 267 women randomized into the trial, 33.7% (n=90) were minorities. Of minority women randomized into the trial, 68.9% (n=62) were recruited by direct mail letters: 75.8% (n=47) of those were sent a letter and 24.2% (n=15) were referred by friends/family who were sent a letter. The results indicate that a simple modification to a standard recruitment letter can have a meaningful impact on minority reach and recruitment rates. Practical implications include using ethnically-targeted, non-personalized direct mail letters and recruiting through friends/family at no additional cost.

Abstract

Few studies have examined the weight-control practices that promote weight loss and weight-loss maintenance in the same sample.To examine whether the weight control practices associated with weight loss differ from those associated with weight-loss maintenance.Cross-sectional survey of a random sample of 1165 U.S. adults. The adjusted associations of the use of 36 weight-control practices in the past week with success in weight loss (?10% lost in the past year) and success in weight-loss maintenance (?10% lost and maintained for ?1 year) were examined.Of the 36 practices, only 8 (22%) were associated with both weight loss and weight-loss maintenance. Overall, there was poor agreement (kappa=0.22) between the practices associated with weight loss and/or weight-loss maintenance. For example, those who reported more often following a consistent exercise routine or eating plenty of low-fat sources of protein were 1.97 (95% CI=1.33, 2.94) and 1.76 (95% CI=1.25, 2.50) times more likely, respectively, to report weight-loss maintenance but not weight loss. Alternatively, those who reported more often doing different kinds of exercises or planning meals ahead of time were 2.56 (95% CI=1.44, 4.55) and 1.68 (95% CI=1.03, 2.74) times more likely, respectively, to report weight loss but not weight-loss maintenance.Successful weight loss and weight-loss maintenance may require two different sets of practices. Designing interventions with this premise may inform the design of more effective weight-loss maintenance interventions.

Abstract

The Jade Ribbon Campaign (JRC) is a culturally targeted, community-based outreach program to promote the prevention, early detection, and management of chronic hepatitis B virus (HBV) infection and liver cancer among Asian Americans. In 2001, 476 Chinese American adults from the San Francisco Bay Area attended an HBV screening clinic and educational seminar. The prevalence of chronic HBV infection was 13%; only 8% of participants showed serologic evidence of protective antibody from prior vaccination. Participants reported low preventive action before the clinic, but after one year, 67% of those with chronic HBV infection had consulted a physician for liver cancer screening, and 78% of all participants had encouraged family members to be tested for HBV. The increase in HBV awareness, screening, and physician follow-up suggests that culturally aligned interventions similar to the JRC may help reduce the disproportionate burden of disease to chronic HBV infection among Asian Americans.

Abstract

In recognition of the increasingly important role of moderators and mediators in clinical research, clear definitions are sought of the two terms to avoid inconsistent, ambiguous, and possibly misleading results across clinical research studies.The criteria used to define moderators and mediators proposed by the Baron & Kenny approach, which have been long used in social/behavioral research, are directly compared to the criteria proposed by the recent MacArthur approach, which modified the Baron & Kenny criteria.After clarifying the differences in criteria between approaches, the rationale for the modifications is clarified and the implications for the design and interpretation of future studies considered.Researchers may find modifications introduced in the MacArthur approach more appropriate to their research objectives, particularly if their research might have a direct influence on decision making.

Abstract

Given pediatric cancer patients are living into adulthood, parents and patients need to be informed about fertility-related side effects of their particular treatment.We surveyed 97 parents of pediatric patients of all ages as well as 37 adolescent patients of 14 years or older who were presented for care at the Lucile Packard Children's Hospital (LPCH) at the Stanford University Medical Center. We estimated the potential infertility risk (low, intermediate, and high) based on the child's treatment regimen.In contrast to our hypothesis, the majority of parents in all three risk categories were concerned about fertility-related side effects of cancer treatment. Many parents with children at low risk were concerned (58.3%) whereas not all parents with children at intermediate or high risk were concerned, 61.5% and 73.3% respectively, P = 0.43. Indeed, over 50% of all parents were erroneously concerned that cancer therapies cause DNA damage to their child's eggs (or sperm). Only 29.9% of parents were satisfied with the amount of information received. Similar patterns were seen among the adolescent patient sample.Parents of pediatric cancer patients and teenage patients have concerns about fertility-related side effects regardless of treatment received. Targeted education about infertility risk before and after treatment can address these gaps.

Abstract

To examine whether the use of a community mobile health van (the Lucile Packard Childrens Hospital Women's Health Van) in an underserved population allows for earlier access to prenatal care and increased rate of adequate prenatal care, as compared to prenatal care initiated in community clinics.We studied 108 patients who initiated prenatal care on the van and delivered their babies at our University Hospital from September 1999 to July 2004. One hundred and twenty-seven patients who initiated prenatal care in sites other than the Women's Health Van, had the same city of residence and source of payment as the study group, and also delivered their babies at our hospital during the same time period, were selected as the comparison group. Gestational age at which prenatal care was initiated and the adequacy of prenatal care - as defined by Revised Graduated Index of Prenatal Care Utilization (RGINDEX) - were compared between cases and comparisons.Underserved women utilizing the van services for prenatal care initiated care three weeks earlier than women using other services (10.2 +/- 6.9 weeks vs. 13.2 +/- 6.9 weeks, P = 0.001). In addition, the data showed that van patients and non-van patients were equally likely to receive adequate prenatal care as defined by R-GINDEX (P = 0.125).Women who initiated prenatal care on the Women's Health Van achieved earlier access to prenatal care when compared to women initiating care at other community health clinics.

Abstract

To determine the effectiveness and safety of image-guided robotic radiosurgery for spinal metastases.From 1996 to 2005, 74 patients with 102 spinal metastases were treated using the CyberKnife at Stanford University. Sixty-two (84%) patients were symptomatic. Seventy-four percent (50/68) of previously treated patients had prior radiation. Using the CyberKnife, 16-25 Gy in 1-5 fractions was delivered. Patients were followed clinically and radiographically for at least 3 months or until death.With mean follow-up of 9 months (range 0-33 months), 36 patients were alive and 38 were dead at last follow-up. No death was treatment related. Eighty-four (84%) percent of symptomatic patients experienced improvement or resolution of symptoms after treatment. Three patients developed treatment-related spinal injury. Analysis of dose-volume parameters and clinical parameters failed to identify predictors of spinal cord injury.Robotic radiosurgery is effective and generally safe for spinal metastases even in previously irradiated patients.

Abstract

Given the higher survival rates of childhood cancer, health care providers must be aware of the side effects of cancer therapies to educate patients and provide appropriate interventions to reduce cancer-related morbidity. To understand the current practices and attitudes in a pediatric hematology/oncology clinic, health care providers were surveyed regarding fertility issues pertinent to their patient care. PARTICIPANTS AND INSTRUMENTS: In this study, 93.8% (30/32) health care providers in one pediatric hematology/oncology department completed a 44-item survey assessing knowledge, current practices, obstacles to current practices, perceptions of patient differences, and improvements to future practice.The majority of health care providers were aware of the adverse effects of alkylating agents (90.7%) and of abdominal and pelvic radiation (100.0%) on fertility. However, only half were aware of gender differences in gonadotoxicity (50.0%) or knowledgeable of current research and technology in fertility preservation (53.3%). While only 34.6% of providers currently consulted with specialists, nearly all (92.8%) indicated a desire to do so in the future, but 64.3% indicated difficulties in finding proper facilities and specialists for their patients. Almost all (96.6%) agreed that providers and patient families need more information regarding the effects of cancer therapy on fertility.Surveyed pediatric oncology providers considered fertility to be an important issue for childhood cancer patients and desired more resources regarding effects on fertility and fertility preservation. Greater communication needs to be established between pediatric oncology providers and specialists in reproductive medicine and endocrinology to ensure adequate professional collaboration and patient referrals.

Abstract

To identify and characterize subgroups of a pediatric population at risk of poor emergency department (ED) aftercare compliance.This was a prospective, cohort study conducted at a university hospital ED with a 2003 pediatric census of 11,040 patients. A convenience sample of 461 children was enrolled. The study follow-up rate was 97%. The primary outcomes were guardian compliance with instructions for physician follow-up appointment and with obtaining prescribed medications. Predictors of compliance outcomes were analyzed by using recursive partitioning to describe population subgroups at risk of poor compliance.Only 60.4% of patient guardians followed up with instructions to see a physician. Children with private insurance were more likely to follow up than were children without private insurance (76.8% vs. 46.5%, p < 0.001). Of children with private insurance, those with high-acuity diagnoses were more likely to follow up than were patients with low-acuity diagnoses (80.0% vs. 38.5%, p < 0.001). Of children who were considered underinsured (defined as publicly insured or uninsured), those with English-speaking guardians were more likely to follow up than were those with non-English-speaking guardians (58.0% vs. 40.0%, p < 0.05). Only 63.3% of patient guardians obtained prescribed medications. Privately insured children were more likely to obtain medications than were underinsured children (71.0% vs. 58.0%, p < 0.05). Descriptive profiles of the subgroups revealed that those with lower socioeconomic status were at greatest risk of poor aftercare compliance.Compliance with ED aftercare instructions remains a challenge. Health insurance disparities are associated with poor ED aftercare compliance in our pediatric population. Interventions aimed at improving compliance could be targeted to specific subgroups on the basis of their descriptive profiles.

Abstract

To review sentinel lymph node (SLN) data from Stanford University Medical Center from January 1, 1997, to January 1, 2004, including rates of SLN positivity according to 2002 American Joint Committee on Cancer (AJCC) tumor classification, relation to other clinical and pathologic prognostic factors, and rates and sites of melanoma recurrence.Retrospective case series.Stanford University Medical Center and Stanford melanoma clinics.A total of 274 consecutive patients with primary melanoma who underwent SLN biopsy (SLNB) between January 1, 1997, and January 1, 2004, or who were referred to the Stanford melanoma clinics after SLNB and were followed up through March 2005.All patients underwent standard wide local excision of their primary tumors and SLNB with intradermal injection of isosulfan blue dye and/or technetium sulfur colloid.Rates of SLN positivity per 2002 AJCC tumor classification, relation to other clinical and pathologic prognostic factors, and rates and sites of melanoma recurrence in node-negative and node-positive patients.Positive SLNs were detected in 39 (15%) of 260 cases, including 0 (0%) of 45 for cutaneous melanomas 1.0 mm thick or less (T1), 21 (18%) of 115 for melanomas 1.01 to 2.0 mm thick (T2), 12 (19%) of 64 for melanomas 2.01 to 4.0 mm thick (T3), and 5 (16%) of 32 for melanomas thicker than 4.0 mm (T4). Median Breslow depths were 1.89 mm for SLN-positive biopsy specimens and 1.50 mm for SLN-negative biopsy specimens (P = .07). The recurrence rate was 46% among SLN-positive patients, with a median time to recurrence of 8 months. Bivariate analysis revealed SLN positivity to be associated with AJCC tumor classification (P = .02), location on the trunk (P = .03), and presence of ulceration (P = .03). By multivariate logistic regression, ulceration (P = .01) was predictive of SLN positivity, whereas SLN status (P< .001), ulceration (P = .02), and location (P = .03) were predictive of recurrent disease.Data from the past 8 years confirm the accuracy and prognostic value of SLNB in cutaneous melanoma and the low rate of regional nodal recurrence for SLN-negative patients.

Abstract

Adding exercise to a comprehensive weight-loss program might not only attenuate any psychological distress associated with weight-loss attempts but also may provide psychological benefits. This study examined whether a diet-plus-exercise weight-loss program improved psychological outcomes more than a diet-only weight-loss program or an assessment-only control group.This study was part of a larger 1-year randomized weight-loss trial examining the effects of diet and exercise on cardiovascular disease risk factors in 264 overweight adults. Psychological measures specific to weight control (e.g., cognitive restraint, disinhibition, hunger, and body dissatisfaction) as well as traditional measures of psychological distress (e.g., symptoms of depression, anxiety, and stress) were obtained at baseline and 1 year.Men and women in either weight-loss program reported greater restraint, less disinhibition, and less hunger at 1 year than those in no program. Men in the diet-plus-exercise program experienced additional increases in restraint and decreases in hunger than did men in the diet-only program. Women in the diet-plus-exercise program did not experience additional psychological benefits specific to weight control than those in the diet-only program, despite increases in aerobic capacity.The pattern seen for overweight men in the diet-plus-exercise program at 1 year-greater restraint, less disinhibition, and less hunger-is similar to the pattern seen in successful weight maintainers. These results underscore the need for innovative strategies that will enhance and sustain the pattern of psychological benefits specific to weight control associated with successful weight loss, especially for overweight women.

Abstract

Identifying parental behaviors that influence childhood obesity is critical for the development of effective prevention and treatment programs. Findings from a prior laboratory study suggest that parents who impose control over their children's eating may interfere with their children's ability to regulate intake, potentially resulting in overweight. These findings have been widely endorsed; however, the direct relationship between parental control of children's intake and their children's degree of overweight has not been shown in a generalized sample.This study surveyed 792 third-grade children with diverse ethnic and socioeconomic backgrounds from 13 public elementary schools. Parental control over children's intake was assessed through telephone interviews using a state-of-the-art instrument, and children were measured for height, weight, and triceps skinfold thickness.Counter to the hypothesis, parental control over children's intake was inversely associated with overweight in girls, as measured by body mass index, r = -0.12, p < 0.05, and triceps skinfolds, r = -0.11, p < 0.05. This weak relationship became only marginally significant when controlling for parents' perceptions of their own weight, level of household education, and children's age. No relationship between parental control of children's intake and their children's degree of overweight was found in boys.Previous observations of the influence of parental control over children's intake in middle-class white families did not generalize to 8- to 9-year-olds in families with diverse socioeconomic and ethnic backgrounds. The present findings reveal a more complex relationship between parental behaviors and children's weight status.

Abstract

Identifying subgroups of high-risk individuals can lead to the development of tailored interventions for those subgroups. This study compared two multivariate statistical methods (logistic regression and signal detection) and evaluated their ability to identify subgroups at risk. The methods identified similar risk predictors and had similar predictive accuracy in exploratory and validation samples. However, the 2 methods did not classify individuals into the same subgroups. Within subgroups, logistic regression identified individuals that were homogeneous in outcome but heterogeneous in risk predictors. In contrast, signal detection identified individuals that were homogeneous in both outcome and risk predictors. Because of the ability to identify homogeneous subgroups, signal detection may be more useful than logistic regression for designing distinct tailored interventions for subgroups of high-risk individuals.

Abstract

Physical activity and physical fitness are complex entities comprising numerous diverse components that present a challenge in terms of accurate, reliable measurement. Physical activity can be classified by its mechanical (static or dynamic) or metabolic (aerobic or anaerobic) characteristics and its intensity (absolute or relative to the person's capacity). Habitual physical activity can be assessed by using a variety of questionnaires, diaries, or logs and by monitoring body movement or physiologic responses. Selection of a measurement method depends on the purpose of the evaluation, the nature of the study population, and the resources available. The various components of physical fitness can be assessed accurately in the laboratory and, in many cases, in the field by using a composite of performance tests. Most coaches and high-level athletes would accept as very beneficial a dietary supplement that would increase performance in a competitive event by even 3%; for example, lowering a runner's time of 3 min, 43 s in the 1500 m by 6.7 s. To establish that such small changes are caused by the dietary supplement requires carefully conducted research that involves randomized, placebo-controlled, double-blind studies designed to maximize statistical power. Statistical power can be increased by enlarging sample size, selecting tests with high reliability, selecting a potent but safe supplement, and maximizing adherence. Failure to design studies with adequate statistical power will produce results that are unreliable and will increase the likelihood that a true effect will be missed.

Abstract

The NHLBI (National Heart, Lung, and Blood Institute) Obesity Education Initiative Expert Panel recently proposed that clinicians and other health care professionals use a new treatment algorithm to identify patients for weight-loss treatment. In addition to the usual assessment of body mass index (BMI, calculated as weight in kilograms divided by the square of height in meters), the new algorithm includes the assessment of abdominal obesity (as measured by waist circumference) and other cardiovascular disease (CVD) risk factors.We examined the percentage of adults meeting the criteria of the panel's treatment algorithm: BMI > or =30 or ¿[BMI, 25.0-29.9 or waist circumference >88 cm (women) >102 cm (men)] and > or = 2 CVD risk factors¿ in a sample of 2844 black, 2754 Mexican American, and 3504 white adults, aged 25 to 64 years, from the Third National Health and Nutrition Examination Survey, 1988-1994.Across ethnic groups, more than 98% of adults (normal weight, overweight, and obese) received the same treatment recommendations using the panel's algorithm and an algorithm based only on BMI and CVD risk factors, without waist circumference. For normal-weight adults, almost none (0.0%-1.8%) had a large waist circumference as defined above and 2 or more CVD risk factors. Using the usual criterion of a BMI of 30 or higher, a substantial percentage of at-risk overweight women and men (BMI, 25.0-29.9) with 2 or more CVD risk factors were missed (8.4% and 19.3%, respectively).Despite the potential importance of abdominal obesity as a CVD risk factor, these results challenge the clinical utility of including waist circumference in this new algorithm and suggest that using BMI and CVD risk factors may be sufficient.

Abstract

Identifying strategies for successful recruitment of ethnic minorities into scientific studies is critical. Without effective methods, investigators may fail to recruit the desired sample size, take longer to recruit than planned, and delay progress for research in minority health. Direct mail is an appealing recruitment method because of the potential for reaching large target populations and producing a high volume of inquiries about a study with relatively little staff effort. To determine which of three direct mail strategies yielded higher recruitment, 561 Hispanic employees were randomly assigned to receive either: (a) a flyer about a worksite dietary intervention; (b) the same flyer plus a personalized hand-signed letter containing heart disease risk statistics for the general American population; or (c) the flyer plus a personalized hand-signed letter containing statistics for Hispanics. Two orthogonal chi-square comparisons were examined. The personalized letters plus flyer yielded a significantly higher response rate (7.8%) than the flyer alone (2.1%), X2(1, N = 561) = 7.5, p = .006. However, the personalized letter with Hispanic heart disease risk statistics did not yield a statistically significant higher response rate (9.1%) than the letter with the general population risk statistics (6.5%), X2(1, N = 370) = 0.9, p > .34. These findings suggest that personalized approaches can increase the effectiveness of direct mail efforts for recruiting ethnic minorities into interventions and may be particularly helpful for large-scale interventions.

Abstract

The potential effects of making a marital transition on subsequent physical activity were evaluated across a ten-year period in a population-based sample of 302 women and 256 men ages 25 to 75 years. Subjects completed a structured interview at five timepoints throughout the ten-year period during which they reported on their physical activity level as well as marital status. The transition from a married to a single state did not affect physical activity relative to remaining married when analyses of either slopes or mean values were used. In contrast, the transition from a single to a married state resulted in significant positive changes in physical activity relative to remaining single throughout the study period when physical activity slopes, though not means, were compared. The results suggest that marriage may potentially set the stage for natural changes in physical activity that could be capitalized on through appropriate intervention, but additional research is needed to verify this in light of the inconsistent pattern of findings.

Abstract

Signal detection methods were used to identify predictors of successful weight loss in 177 mildly to moderately overweight women and men assigned to one of two weight-loss programs. Predictors included initial demographic, physiological, behavioral, and psychosocial characteristics, and program type (e.g. diet-only and diet-plus-exercise). Successful weight loss was defined as a loss of at least two units of body mass index at one year. Four subgroups were identified. Participants in the diet-plus-exercise program who were initially more satisfied with their bodies and did not have a history of repeated weight loss were most likely to succeed (63% succeeded). In contrast, participants assigned to the diet-plus-exercise program who were either extremely dissatisfied with their bodies or who had a history of repeated weight loss were at similar risk for failure as participants in the diet-only program (only 26% to 35% succeeded). The results underscore the potential utility of exploring these subgroups further to inform the development of new treatment strategies to increase the likelihood of success.

Abstract

Signal detection methodology was used to identify the best combination of predictors of long-term exercise adherence in 269 healthy, initially sedentary adults ages 50-65 years. Less educated individuals who were assigned to supervised home-based exercise of either higher or lower intensity and who were less stressed and less fit at baseline than other individuals had the greatest probability of successful adherence by the 2nd year. Overweight individuals assigned to a group-based exercise program were the least likely to be successful 2 years later. Predictors of short-term (1-year) adherence were generally similar to predictors of 2-year adherence. Signal detection analysis may be useful for identifying subgroups of people at risk for underadherence who subsequently might be targeted for intervention.

Abstract

We examined the association between level of exercise and degree of weight preoccupation in a large sample of male and female runners, as well as risk factors posited to influence weight and eating concerns in the general population. Subjects were 2,459 males and 1,786 females who had completed a questionnaire on weight and eating concerns in a national running magazine. Eight percent of the males and 24% of the females had symptomatic scores on the Eating Attitudes Test (EAT). Exercise level, defined as weekly running mileage, was positively associated with excessive weight and eating concerns in males but not in females. Both sexes with a history of weight cycling were more likely to have symptomatic EAT scores than those with no such history. These results highlight the importance of studying these concerns in males as well as females and of examining the role of exercise level and weight-cycling history in the development of serious weight preoccupations.